I've driven both, and, by far the Volvo is a more user friendly car. The Bimmer does handle a bit better, but it is far less comfortable to drive and the iDrive is extremely hard to get used to and operate (and I work at RadioShack). Plus, it is far less costly to pimp out the S60R (i.e. turbo upgrades, ECU upgrades, etc.). I am in the process of making a 550 WHP S60R sitting pretty on 22x10 giovanni's on pirelli rubbers. All in all it will cost me less then $50K total, including the price of the car ($30K). So, choose the R, if not for what I stated above, then because there are far less of them on the roads then the Bimmer.
Never mind the 330 xi, a lot smaller car. I am not a big guy but when I test drove one with my dad who is also not that big, our shoulders were very close and at time touched, so up to the 5 series we went.
I test drove the s60r and a BMW 530xi
Volvo hands down.
Mr R was more powerful, more comfortable, more versatile and out cornered its german friend.
Volvo lot better vehicle at a more comfortable price tag.